Why Magnesium Matters
By Catherine Guthrie
What’s not to love about magnesium? The mineral juices every cell in the body and has a hand in more than 300 biochemical reactions. Subtract it from the bodily equation and nerves stutter, insulin goes haywire, and the heart’s steadfast beat loses its rhythm.
And that’s only the half of it. A lack of the mineral can make matters worse for the millions of people who suffer from migraines and PMS; a shortage also contributes to osteoporosis by preventing the body from absorbing calcium. In sufficient amounts, on the other hand, magnesium can ease symptoms of heart disease and diabetes. It may even help ward off hypertension, a condition that strikes one in four adults in this country.
The problem is that magnesium doesn’t abound in food, so many people aren’t getting enough. “I’m a big fan of a healthy diet,” says Carolyn Dean, a general practitioner in City Island, New York and author of The Miracle of Magnesium, “but getting enough magnesium from food alone is virtually impossible.” Whole grains, leafy greens, beans, avocados, and nuts are good sources, but they’re hardly everyday fare.
In fact, up to 80 percent of people in the United States may be magnesium deficient. You know things are bad when the conservative National Academy of Sciences admits its own recommended daily allowance (RDA) is low: Four years ago it did just that, bumping up the RDA to 320 milligrams. But that doesn’t mean people took note; most likely they just fell further behind.
The upshot is that most of us could use a magnesium boost, says Cynthia Sass, a spokesperson for the American Dietetic Association. If your diet is high in foods that deliver the mineral, she recommends a multivitamin with at least 50 percent of the RDA. If it’s less than stellar, bump that to 80 percent. Here’s what you’ll get in return.
One of the best-kept secrets is that magnesium is essential to calcium absorption—and that many women fall woefully short. Most take calcium to prevent osteoporosis, but because they’re not getting enough magnesium, their calcium isn’t able to do its job.
“Leaving magnesium out of the osteoporosis discussion is a dreadful fault on the part of the health establishment,” says Mildred Seelig, a physician and nutritionist who has studied magnesium for nearly 40 years. “Taking calcium without magnesium gives women a false sense of security.”
The body’s ideal ratio of calcium to magnesium is two to one, she says, which means if you’re getting the 1,200 recommended mg of calcium each day (that’s for postmenopausal women; if you’re premenopausal, it’s 1,000 mg), you should also have 500 mg of magnesium. However, because magnesium is so often overlooked, women’s intake is creeping closer to a 6-to-1 ratio. Seelig suggests a combo supplement with both minerals in one pill.
PMS and headache relief
Premenopausal women would do well to keep their eye on the mineral as well, in part for the same osteoporosis protection, but also to ease symptoms of PMS. In one study, PMS sufferers who downed 200 milligrams of magnesium daily had significantly less bloating and weight gain than those on dummy pills. As a natural diuretic, magnesium boots sodium and water out of the tissue and into the bloodstream so it can be excreted by the kidneys.
Magnesium may also be helpful for people who suffer from migraine headaches. Scientists suspect it helps by widening blood vessels that otherwise constrict and impede blood flow to the brain. And it appears to control the availability of brain messengers like serotonin, which for some people keep migraines at bay. Blood pressure control
Experts have long studied magnesium as a preventive for hypertension, since it’s the mineral that tells arteries when to relax. In one of the most widely touted studies, researchers monitored the diets of more than 30,000 men for four years. By the end of that time, those who ate the most magnesium-rich foods had a significantly lower risk of hypertension than volunteers who skimped on the nutrient.
Certainly anyone at risk for high blood pressure, which includes people who are obese or who have a family history of the disease, should make sure they’re getting enough magnesium. But since hypertension is so common, it wouldn’t hurt us all to stay well stocked.
Better heart health
Last March, the American Journal of Cardiology published some of the most convincing evidence to date on the relevance of magnesium to heart health.
In a study of 187 people with coronary artery disease, those who received 365 milligrams of magnesium twice a day for six months reported a “significant improvement” in their general pain levels; the placebo group saw little to no change. One tangible benefit: Magnesium-takers enjoyed a 14 percent gain in the amount of time they could exercise without chest pain.
The mineral likely worked by widening patients’ arteries, thus creating better blood flow, says Noel Bairey Merz, medical director of preventive cardiac programs at Cedars-Sinai Medical Center in Los Angeles and one of the study’s authors. Magnesium also thins blood and regulates abnormal heart rhythms.
Milder diabetes symptoms
No one knows for sure whether low magnesium causes diabetes, but it’s widely recognized as a marker for the disease and occurs in up to 40 percent of diabetes patients.
Experts do know that a person with a chronic magnesium shortfall is more likely to experience complications of the disease. In a study published last April in Diabetes Care, patients with type 2 diabetes who took magnesium for 16 weeks had significantly greater insulin sensitivity (meaning they were able to cut their insulin dosage) than those who swallowed a placebo.
Magnesium Users’ Guide
What is it? A mineral that’s vital to every cell in the body.
Dosage: The RDA for magnesium is 320 milligrams for women (350 during pregnancy) and 420 mg for men, which should be enough to control PMS and headaches and ward off high blood pressure. (In one PMS study the women took much more: 360 mg three times a day.) You may also need more than the RDA if you have heart disease or diabetes, but you should ask your practitioner to recommend an appropriate amount. Magnesium citrate and magnesium oxidate are two of the least expensive and most user-friendly forms.
Risks: Magnesium supplements are remarkably safe. But too much of the nutrient may cause diarrhea, which can be alleviated by taking the supplement either with food or in two separate doses. Since the kidneys regulate the body’s magnesium level, people with kidney disease shouldn’t take more than the RDA. The mineral also blocks the effectiveness of some antibiotics, specifically tetracycline, minocycline, and doxycycline, so avoid taking magnesium supplements within three hours of taking these medications.